1. Technical Field
The present invention relates to a printed circuit board, more particularly, to a printed circuit board having embedded electronic components and manufacturing method thereof.
2. Description of the Related Art
As a part of next-generation multi-functional miniature package technology, attention is being focused on the development of a printed circuit board having embedded electronic components. Along with the advantages of multi-functionality and miniaturization, a printed circuit board having embedded electronic components also allows, to a degree, more sophisticated functionalities, as the wiring distance can be minimized in a high-frequency range of 100 MHz or higher, and in some cases, problems in reliability may be resolved for connections between components using wire bonding or solder balls in an FC (flip chip assembly) or a BGA (ball grid array).
However, in a conventional printed circuit board having embedded electronic components, there is a high probability that problems in heat release due to embedding electronic components such as high-density IC's, or problems such as delamination, etc., will affect the yield, and there are difficulties in the overall process that raise the costs of manufacture. Therefore, a technology is required which provides strength for minimizing warpage in thin printed circuit boards, and which provides improvements in heat-releasing property.
Also, the process of embedding electronic components has hitherto involved a structure in which the electronic components are embedded in only one side of the core substrate, or in only one side of the build-up layer, which is inevitably vulnerable to bending in a thermal-stress environment. Thus, there has been a fundamental limit to increasing the number of electronic components embedded.
Examples in related art of the printed circuit board having embedded electronic components include, first, a method of utilizing tape and a molding compound for embedding the electronic components, as shown in FIG. 1. In this invention, liquid epoxy material is utilized in embedding the components after etching an insulation substrate, so as to minimize the thermal and mechanical impact caused by differences in the coefficients of thermal expansion and the coefficients of elasticity between the embedded electronic components, such as IC's, and the substrate. However, it is limited in that the strength and heat-releasing property of the substrate itself are unchanged, and that it involves an asymmetric structure.
A second example includes an invention in which condensers are stacked on both sides of a core substrate for higher-density stacking. However, this considers only the matter of higher-density stacking, and is limited in that it does not consider the heat-releasing property of the substrate, and that it does not complement bending strength by forming a symmetrical structure.